The posts for the front frame are made from .125 x .5 x 2-inch tubes. First thing was to stuff the bottoms with the screw blocks/nuts in order to eventually attach them to the bottom sheet.
Following standard operating procedure, the aluminum was cut on my miter saw (fitted with a standard carbide tipped blade). The clamp that came with the saw is used to hold the material against the fence.
The blocks were then drilled on the drill press with the assistance of my self-centering vice (I love
that thing because I don't have to waste time measuring for center).
Threads were tapped via my bench mounted "hand" tapper.
The blocks were pinned to the tubes with flat head self-tapping screws.
Always looking to improve my speed and quality, the cross supports offered the opportunity to use PEM cinch nuts. The nuts were pressed into the screw blocks.
Which were then pinned inside .5 x 1-inch u-channel.